Yeah, you probably should have put a smock on your kid or at least put on an old sweatshirt before starting that at-home art project, but hindsight is 20/20. Next time you promise to be more careful.
Well I don't know much about model paint, but the texture of a surface that's been vinyl dyed is almost identical to the original plastic. So if it's not shiny to begin with, it probably won't be ...